Carl,
See it all depends upon your network arhcitecture. In some scenarios you dont require distribution and some times no access and it also depends upon your budget i.e. how much you want to spend on IT.
In Some companies they use 2950 at access layer and 4500 at Core/Distribution.
In Some companies they 6500 series at access, distribution and core layers.
In a hierarchical design/3 -ties architecture Core->Distribution -> Access, this job is processed at distribution layer.
The ACLs processing and the traffic filtering is offloaded to the distribution layer rather then being handled by the Core layer.
The overall idea of it is to offload core from processing the unwanted tarrafic and do the filtering of the trafiic which can eventually decrease the performance of a Core switch.
We want our core to handle a large amount of traffic and switch it as efficiently it can so the procesing of ACL's, Inter-vlan routing, traffic filtering is done by the distribution layer.
Hope that helps.
Please rate the posts.
Regards,
Suresh Jain
